Quantum materials exhibit emergent phenomena, such as superconductivity, charge ordering, and topological states, that arise only at cryogenic temperatures. Local features, including interfaces, defects, and moiré superlattices, are becoming increasingly important for tuning electronic, magnetic, and topological properties in these systems. studying the impact of these features on influencing quantum phase transitions and correlated behaviors requires advanced techniques capable of resolving lattice, spin, and charge correlations with sub-nanometer precision. Scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS) offer high spatial, energy, and momentum resolution, yet their cryogenic implementation has long been limited by mechanical and thermal instabilities. Recent developments in liquid-nitrogen- and liquid-helium-cooled STEM–EELS platforms now enable stable, high-resolution imaging and spectroscopy at cryogenic temperatures.

This talk will highlight the integration of newly developed cryogenic stages with advanced methods, such as 4D-STEM Lorentz imaging and monochromated EELS, to probe quantum materials at the nanoscale. Case studies include magnetic textures in 2D magnets, phase transitions in layered trichalcogenides, and spin–orbital coupling in moiré-structured systems, revealing direct correlations between atomic structure and emergent quantum phenomena.

Biography:

Miaofang Chi is a professor at Duke University and a Corporate Fellow at Oak Ridge National Laboratory (ORNL). She received her Ph.D. in Materials Science and Engineering from the University of California, Davis, in 2008, and conducted her thesis research as a fellow at Lawrence Berkeley and Lawrence Livermore National Laboratory (LBNL&LLNL) from 2004-2008. Her primary research interests include understanding interfacial charge transfer and ion transport behavior in energy and quantum materials by advancing and employing novel electron microscopy techniques. She is a Fellow of the Microscopy Society of America (MSA), Materials Research Society (MRS), and the Royal Society of Chemistry (RCS).

Address:United States